| 1 |
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#define MICRODISC_LOADER |
| 2 |
#include "disk_info.h" |
#include "disk_info.h" |
| 3 |
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| 4 |
#define COLOR(color) pha:lda #16+(color&7):sta $bb80+40*27:pla |
#define COLOR(color) pha:lda #16+(color&7):sta $bb80+40*27:pla |
| 5 |
#define STOP(color) pha:lda #16+(color&7):sta $bb80+40*27:jmp *:pla |
#define STOP(color) pha:lda #16+(color&7):sta $bb80+40*27:jmp *:pla |
| 6 |
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| 13 |
current_track .dsb 1 ; Index of the track being loaded |
current_track .dsb 1 ; Index of the track being loaded |
| 14 |
current_sector .dsb 1 ; Index of the sector being loaded |
current_sector .dsb 1 ; Index of the sector being loaded |
| 15 |
current_side .dsb 1 ; Has the bit 4 set to 0 or 1 to be used as a mask on the Microdisc control register (other bits have to be set to zero) |
current_side .dsb 1 ; Has the bit 4 set to 0 or 1 to be used as a mask on the Microdisc control register (other bits have to be set to zero) |
| 16 |
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irq_save_a .dsb 1 ; To preserve the accumulator value in the IRQ code |
| 17 |
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| 18 |
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; Unpack test |
| 19 |
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ptr_source .dsb 2 ; Packed source data adress |
| 20 |
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ptr_destination .dsb 2 ; Destination adress where we depack |
| 21 |
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ptr_destination_end .dsb 2 ; Point on the end of the depacked stuff |
| 22 |
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ptr_source_back .dsb 2 ; Temporary used to hold a pointer on depacked stuff |
| 23 |
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offset .dsb 2 |
| 24 |
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mask_value .dsb 1 |
| 25 |
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nb_dst .dsb 1 |
| 26 |
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| 27 |
.text |
.text |
| 28 |
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| 29 |
; FFF0 |
*=location_loader |
| 30 |
; FFF1 |
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; FFF2 |
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; FFF3 |
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; FFF4 |
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; FFF5 |
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; FFF6 |
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; FFF7 |
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; FFF8 |
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; FFF9 - Test Overlay |
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; |
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; FFFA - NMI Vector (Usually points to $0247) |
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; FFFB |
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; |
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; FFFC - RESET Vector (Usually points to $F88F) |
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; FFFD |
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| 31 |
; |
; |
| 32 |
; FFFE - IRQ Vector (Normally points to $0244) |
; This is called from the bootsectors with the X register containing the fdc offset; |
| 33 |
; FFFF |
; +$00 = Microdisc |
| 34 |
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; +$e4 = Jasmin |
| 35 |
; |
; |
| 36 |
*=location_loader |
Initialize |
| 37 |
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jmp StartUp |
| 38 |
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| 39 |
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#define LOADER |
| 40 |
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| 41 |
Initialize |
; This file is generated by the floppy builder |
| 42 |
jsr SetUpIrqHandlers |
#include "floppy_description.h" |
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jsr SoftHiresWithCopyCharset |
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; Load the picture |
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ldx #0 |
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jsr LoadData |
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;STOP(1) |
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jsr ExecuteData |
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; Load the rasters crap |
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;STOP(1) |
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;ldx #1 |
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;jsr LoadData |
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;jsr SoftHires ; Delete the screen |
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;STOP(2) |
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;jsr ExecuteData |
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; Load the demo |
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jsr SoftHires ; Delete the screen |
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;STOP(1) |
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ldx #2 |
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jsr LoadData |
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;STOP(2) |
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jsr ExecuteData |
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; |
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; End of demo - Just stay there doing nothing |
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; |
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sei |
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.( |
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loop |
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jmp loop |
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.) |
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ClearZeroPage |
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.( |
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lda #0 |
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tax |
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loop |
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sta $00,x |
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dex |
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bne loop |
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rts |
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.) |
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| 43 |
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| 44 |
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; Some local variables we need |
| 45 |
SetUpIrqHandlers |
fdc_register_offset .dsb 1 |
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sei |
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| 46 |
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| 47 |
; Set-up a safe irq that does nothing - Good to avoid crashes |
StartUp |
| 48 |
lda #<IrqDoNothing |
stx fdc_register_offset ; Store the FDC offset value |
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sta $fffa |
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sta $fffc |
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lda #>IrqDoNothing |
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sta $fffb |
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sta $fffd |
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ldy #<IrqHandler |
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lda #>IrqHandler |
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sty $fffe |
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sta $ffff |
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; Make sure the microdisc IRQ is disabled |
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jsr WaitCompletion |
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lda #%10000100 ; Disable the FDC (Eprom select + FDC Interrupt request) |
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sta MICRODISC |
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rts |
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| 49 |
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| 50 |
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; Load the slideshow |
| 51 |
SaveA .byt 0 |
ldx #LOADER_INTRO_PART |
| 52 |
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jsr LoadAndRun |
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| 54 |
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ldx #LOADER_MAIN_PART |
| 55 |
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jsr LoadAndRun |
| 56 |
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| 57 |
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LoadAndRun |
| 58 |
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jsr LoadData |
| 59 |
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| 60 |
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; Give control to the application and hope it knows what to do |
| 61 |
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__auto_execute_address |
| 62 |
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jmp $a000 |
| 63 |
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| 64 |
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| 65 |
IrqHandler |
IrqHandler |
| 66 |
sta SaveA |
sta irq_save_a |
| 67 |
pla |
pla |
| 68 |
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pha |
| 69 |
and #%00010000 ; Check the saved B flag to detect a BRK |
and #%00010000 ; Check the saved B flag to detect a BRK |
| 70 |
bne from_brk |
bne from_brk |
| 71 |
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| 72 |
from_irq |
from_irq |
| 73 |
lda SaveA |
#ifdef LOADER_SHOW_DEBUGINFO |
| 74 |
pha |
lda $bfdf |
| 75 |
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eor #1 |
| 76 |
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ora #16 |
| 77 |
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sta $bfdf |
| 78 |
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#endif |
| 79 |
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lda irq_save_a |
| 80 |
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bit $304 |
| 81 |
IrqDoNothing |
IrqDoNothing |
| 82 |
rti |
rti |
| 83 |
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| 89 |
nop |
nop |
| 90 |
lda #16+2 |
lda #16+2 |
| 91 |
sta $bb80+40*27 |
sta $bb80+40*27 |
| 92 |
jmp from_brk |
bne from_brk |
| 93 |
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| 94 |
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| 95 |
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HexData .byt "0123456789ABCDEF" |
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| 96 |
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| 97 |
; X=File index |
; X=File index |
| 98 |
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; A=Low |
| 99 |
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; Y=High |
| 100 |
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SetLoadAddress |
| 101 |
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sta FileLoadAdressLow,x |
| 102 |
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tya |
| 103 |
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sta FileLoadAdressHigh,x |
| 104 |
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rts |
| 105 |
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| 106 |
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| 107 |
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; X=File index |
| 108 |
LoadData |
LoadData |
| 109 |
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;STOP(2) |
| 110 |
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| 111 |
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; We have to start somewhere no matter what, compressed or not |
| 112 |
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jsr StartReadOperation |
| 113 |
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| 114 |
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; Now at this stage we have to check if the data is compressed or not |
| 115 |
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lda FileStoredSizeLow,x |
| 116 |
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cmp FileSizeLow,x |
| 117 |
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bne LoadCompressedData |
| 118 |
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| 119 |
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lda FileStoredSizeHigh,x |
| 120 |
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cmp FileSizeHigh,x |
| 121 |
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bne LoadCompressedData |
| 122 |
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| 123 |
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LoadUncompressedData |
| 124 |
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| 125 |
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; |
| 126 |
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; Loop to read all the sectors |
| 127 |
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; |
| 128 |
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read_sectors_loop |
| 129 |
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jsr ReadNextSector |
| 130 |
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| 131 |
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; Try to let time to an IRQ to play, and during that time copy the sector to the final location |
| 132 |
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cli |
| 133 |
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| 134 |
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ldy #0 |
| 135 |
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loop_copy |
| 136 |
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lda $200,y ; Load the byte from page 2 |
| 137 |
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__auto_write_address |
| 138 |
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sta $c000,y ; Store it to the final location |
| 139 |
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iny |
| 140 |
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bne loop_copy |
| 141 |
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| 142 |
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nop |
| 143 |
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nop |
| 144 |
sei |
sei |
| 145 |
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| 146 |
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; Next sector |
| 147 |
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inc __auto_write_address+2 |
| 148 |
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dec sectors_to_go |
| 149 |
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bne read_sectors_loop |
| 150 |
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| 151 |
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; Data successfully loaded (we hope), so we restore the interrupts |
| 152 |
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cli |
| 153 |
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rts |
| 154 |
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| 155 |
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| 156 |
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LoadCompressedData |
| 157 |
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clc |
| 158 |
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lda FileLoadAdressLow,x |
| 159 |
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sta ptr_destination+0 |
| 160 |
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adc FileSizeLow,x |
| 161 |
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sta ptr_destination_end+0 |
| 162 |
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| 163 |
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lda FileLoadAdressHigh,x |
| 164 |
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sta ptr_destination+1 |
| 165 |
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adc FileSizeHigh,x |
| 166 |
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sta ptr_destination_end+1 |
| 167 |
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| 168 |
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;STOP(2) |
| 169 |
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| 170 |
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jsr UnpackData |
| 171 |
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cli |
| 172 |
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rts |
| 173 |
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| 174 |
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| 175 |
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StartReadOperation |
| 176 |
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sei |
| 177 |
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| 178 |
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ldy fdc_register_offset |
| 179 |
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| 180 |
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; Make sure the microdisc IRQ is disabled |
| 181 |
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jsr WaitCompletion |
| 182 |
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| 183 |
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lda #%10000100 ; Disable the FDC (Eprom select + FDC Interrupt request) |
| 184 |
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sta FDC_flags,y |
| 185 |
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| 186 |
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;jsr WaitCompletion |
| 187 |
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| 188 |
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; |
| 189 |
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; Setup, we use the table to find out where the file is located on the floppy, |
| 190 |
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; where to write it in memory, and how large it is. |
| 191 |
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; |
| 192 |
lda FileLoadAdressHigh,x |
lda FileLoadAdressHigh,x |
| 193 |
sta __auto_execute_address+2 |
sta __auto_execute_address+2 |
| 194 |
sta __auto_write_address+2 |
sta __auto_write_address+2 |
| 195 |
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| 196 |
lda FileLoadAdressLow,x |
lda FileLoadAdressLow,x |
| 197 |
sta __auto_execute_address+1 |
sta __auto_execute_address+1 |
| 198 |
sta __auto_write_address+1 |
sta __auto_write_address+1 |
| 199 |
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| 200 |
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; Starting track |
| 201 |
; Start on side 0 |
ldy #%00000000 ; Side 0 |
| 202 |
lda #0 |
lda FileStartTrack,x ; If the track id is larger than 128, it means it is on the other side of the floppy |
| 203 |
sta current_side |
bpl first_side |
| 204 |
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; The file starts on the second side |
| 205 |
; Starting track |
ldy #FDC_Flag_DiscSide ; Side 1 |
| 206 |
lda FileStartTrack,x |
and #%01111111 ; Mask out the extra bit |
| 207 |
sta current_track |
first_side |
| 208 |
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sty current_side |
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; If >128 it means it is on the other side |
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sec |
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sbc #128 |
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bmi same_side |
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| 209 |
sta current_track |
sta current_track |
| 210 |
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| 211 |
lda #%00010000 |
ldy fdc_register_offset |
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sta current_side |
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same_side |
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| 212 |
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| 213 |
; First sector |
; First sector |
| 214 |
lda FileStartSector,x |
lda FileStartSector,x |
| 215 |
sta current_sector |
sta current_sector |
| 216 |
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| 217 |
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; FileSizeLow/FileSizeHigh |
| 218 |
; Number of sectors to load |
; Number of sectors to load |
| 219 |
lda FileSectorCount,x |
.( |
| 220 |
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lda FileStoredSizeHigh,x |
| 221 |
sta sectors_to_go |
sta sectors_to_go |
| 222 |
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lda FileStoredSizeLow,x |
| 223 |
; Loop to read all the sectors |
beq skip |
| 224 |
read_sectors_loop |
inc sectors_to_go |
| 225 |
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skip |
| 226 |
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.) |
| 227 |
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rts |
| 228 |
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| 229 |
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| 230 |
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ReadNextSector |
| 231 |
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cli |
| 232 |
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| 233 |
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ldy fdc_register_offset |
| 234 |
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| 235 |
; Check if we have reached the end of the track |
; Check if we have reached the end of the track |
| 236 |
lda current_sector |
lda current_sector |
| 237 |
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cmp #FLOPPY_SECTOR_PER_TRACK+1 |
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cmp #17+1 |
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| 238 |
bne same_track |
bne same_track |
| 239 |
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| 240 |
; Next track |
; Next track |
| 241 |
inc current_track |
inc current_track |
| 242 |
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lda current_track |
| 243 |
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cmp #FLOPPY_TRACK_NUMBER |
| 244 |
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bne stay_on_same_side |
| 245 |
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| 246 |
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; Reset to the first track on the other side |
| 247 |
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lda #0 |
| 248 |
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sta current_track |
| 249 |
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| 250 |
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sei |
| 251 |
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| 252 |
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lda #FDC_Flag_DiscSide |
| 253 |
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sta current_side |
| 254 |
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stay_on_same_side |
| 255 |
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| 256 |
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| 257 |
; Reset the sector position |
; Reset the sector position |
| 258 |
lda #1 |
lda #1 |
| 259 |
sta current_sector |
sta current_sector |
| 260 |
same_track |
same_track |
| 261 |
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| 262 |
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#ifdef LOADER_SHOW_DEBUGINFO |
| 263 |
; Display debug info |
; Display debug info |
| 264 |
;jsr DisplayPosition |
cli |
| 265 |
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jsr DisplayPosition |
| 266 |
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sei |
| 267 |
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#else |
| 268 |
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cli |
| 269 |
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jsr WaitCommand |
| 270 |
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sei |
| 271 |
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#endif |
| 272 |
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| 273 |
lda current_sector |
lda current_sector |
| 274 |
sta FDC_sector_register |
sta FDC_sector_register,y |
| 275 |
inc current_sector |
inc current_sector |
| 276 |
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| 277 |
; Check if the drive is on the correct track |
; Check if the drive is on the correct track |
| 278 |
lda current_track |
lda current_track |
| 279 |
cmp FDC_track_register |
cmp FDC_track_register,y |
| 280 |
beq stay_on_the_track |
beq stay_on_the_track |
| 281 |
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| 282 |
; Set the new track |
; Set the new track |
| 283 |
sta FDC_data |
sta FDC_data,y |
| 284 |
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| 285 |
lda #CMD_Seek |
lda #CMD_Seek |
| 286 |
sta FDC_command_register |
sta FDC_command_register,y |
| 287 |
jsr WaitCompletion |
jsr WaitCompletion |
| 288 |
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| 289 |
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stay_on_the_track |
| 290 |
lda #%10000100 ; on force les le Microdisk en side0, drive A ... Set le bit de données !!! |
lda #%10000100 ; on force les le Microdisk en side0, drive A ... Set le bit de données !!! |
| 291 |
ora current_side |
ora current_side |
| 292 |
sta MICRODISC |
sta FDC_flags,y |
| 293 |
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stay_on_the_track |
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| 294 |
lda #CMD_ReadSector |
lda #CMD_ReadSector |
| 295 |
sta FDC_command_register |
sta FDC_command_register,y |
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| 296 |
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| 297 |
ldy #wait_status_floppy |
;cli |
| 298 |
waitcommand |
jsr WaitCommand |
| 299 |
nop |
;sei |
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nop |
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dey |
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bne waitcommand |
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| 300 |
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| 301 |
; |
; |
| 302 |
; Read the sector data |
; Read the sector data |
| 303 |
; |
; |
| 304 |
ldy #0 |
ldx #0 |
| 305 |
microdisc_read_data |
microdisc_read_data |
| 306 |
lda $0318 |
lda $0318 |
| 307 |
bmi microdisc_read_data |
bmi microdisc_read_data |
| 308 |
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| 309 |
lda $313 |
lda FDC_data,y |
| 310 |
__auto_write_address |
sta $200,x ; Store the byte in page 2 |
| 311 |
sta $c000,y |
inx |
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iny |
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| 312 |
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| 313 |
bne microdisc_read_data |
bne microdisc_read_data |
| 314 |
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| 315 |
lda FDC_status_register |
lda FDC_status_register,y |
| 316 |
and #$1C |
and #$1C |
| 317 |
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| 318 |
; Next sector |
jsr WaitCompletion |
| 319 |
inc __auto_write_address+2 |
cli |
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dec sectors_to_go |
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bne read_sectors_loop |
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; Data successfully loaded (we hope) |
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| 320 |
rts |
rts |
| 321 |
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| 322 |
ExecuteData |
WaitCommand |
| 323 |
jsr SetUpIrqHandlers |
ldx #wait_status_floppy |
| 324 |
jsr ClearZeroPage |
waitcommand |
| 325 |
__auto_execute_address |
nop |
| 326 |
jsr $a000 |
nop |
| 327 |
jsr SetUpIrqHandlers |
dex |
| 328 |
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bne waitcommand |
| 329 |
rts |
rts |
| 330 |
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| 331 |
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WaitCompletion |
| 332 |
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txa |
| 333 |
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pha |
| 334 |
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| 335 |
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php |
| 336 |
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sei |
| 337 |
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nop |
| 338 |
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nop |
| 339 |
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nop |
| 340 |
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| 341 |
WaitCompletion |
ldx #4 |
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ldy #4 |
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| 342 |
r_wait_completion |
r_wait_completion |
| 343 |
dey |
dex |
| 344 |
bne r_wait_completion |
bne r_wait_completion |
| 345 |
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plp |
| 346 |
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| 347 |
r2_wait_completion |
r2_wait_completion |
| 348 |
lda FDC_status_register |
lda FDC_status_register,y |
| 349 |
lsr |
lsr |
| 350 |
bcs r2_wait_completion |
bcs r2_wait_completion |
| 351 |
asl |
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| 352 |
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;asl |
| 353 |
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pla |
| 354 |
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tax |
| 355 |
rts |
rts |
| 356 |
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| 357 |
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#ifdef LOADER_SHOW_DEBUGINFO |
| 358 |
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HexData .byt "0123456789ABCDEF" |
| 359 |
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| 360 |
DisplayPosition |
DisplayPosition |
| 361 |
.( |
.( |
| 362 |
lda current_side |
lda current_side |
| 407 |
;jsr WaitLoop |
;jsr WaitLoop |
| 408 |
rts |
rts |
| 409 |
.) |
.) |
| 410 |
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#endif |
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WaitLoop |
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jsr WaitLoop2 |
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jsr WaitLoop2 |
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jsr WaitLoop2 |
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jsr WaitLoop2 |
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rts |
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WaitLoop2 |
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jsr WaitLoop3 |
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jsr WaitLoop3 |
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jsr WaitLoop3 |
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jsr WaitLoop3 |
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rts |
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WaitLoop3 |
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jsr WaitLoop4 |
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jsr WaitLoop4 |
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jsr WaitLoop4 |
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jsr WaitLoop4 |
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rts |
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| 411 |
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| 412 |
WaitLoop4 |
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| 413 |
.( |
GetNextByte |
| 414 |
ldx #0 |
php |
| 415 |
loop |
lda __fetchByte+1 |
| 416 |
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bne __fetchByte |
| 417 |
nop |
nop |
| 418 |
nop |
nop |
| 419 |
nop |
nop |
| 420 |
dex |
nop |
| 421 |
bne loop |
sei |
| 422 |
rts |
jsr ReadNextSector |
| 423 |
.) |
nop |
| 424 |
|
nop |
| 425 |
|
nop |
| 426 |
SoftHiresWithCopyCharset |
nop |
| 427 |
LDY #$00 ;COPY CHARSET |
cli |
| 428 |
HM_03 |
ldx #0 |
| 429 |
LDA $B500,Y |
ldy #0 |
| 430 |
STA $9900,Y |
__fetchByte |
| 431 |
LDA $B600,Y |
lda $200 |
| 432 |
STA $9A00,Y |
inc __fetchByte+1 |
| 433 |
LDA $B700,Y |
plp |
| 434 |
STA $9B00,Y |
rts |
|
LDA $B900,Y |
|
|
STA $9D00,Y |
|
|
LDA $BA00,Y |
|
|
STA $9E00,Y |
|
|
LDA $BB00,Y |
|
|
STA $9F00,Y |
|
|
DEY |
|
|
BNE HM_03 |
|
|
SoftHires |
|
|
LDA #$A0 ;CLEAR DOWN ALL MEMORY AREA WITH ZERO |
|
|
STA $01 |
|
|
LDA #$00 |
|
|
STA $00 |
|
|
LDX #$20 |
|
|
HM_01 STA ($00),Y |
|
|
INY |
|
|
BNE HM_01 |
|
|
INC $01 |
|
|
DEX |
|
|
BNE HM_01 |
|
|
LDA #30 ;WRITE HIRES SWITCH |
|
|
STA $BF40 |
|
|
LDA #$A0 ;CLEAR HIRES WITH #$40 |
|
|
STA $01 |
|
|
LDX #$20 |
|
|
LDX #64 |
|
|
HM_04 |
|
|
LDY #124 |
|
|
HM_05 |
|
|
LDA #$40 |
|
|
STA ($00),Y |
|
|
DEY |
|
|
BPL HM_05 |
|
|
LDA $00 |
|
|
ADC #125 |
|
|
STA $00 |
|
|
BCC HM_02 |
|
|
INC $01 |
|
|
HM_02 DEX |
|
|
BNE HM_04 |
|
|
RTS |
|
| 435 |
|
|
| 436 |
|
|
| 437 |
|
|
| 438 |
|
; void file_unpack(void *ptr_dst,void *ptr_src) |
| 439 |
|
|
| 440 |
|
; Need to be called with valid values in: |
| 441 |
|
; ptr_destination |
| 442 |
|
; ptr_source |
| 443 |
|
; ptr_destination_end (Destination + size) |
| 444 |
|
UnpackData |
| 445 |
|
;jmp UnpackData |
| 446 |
|
.( |
| 447 |
|
cli |
| 448 |
|
|
| 449 |
|
; Initialise variables |
| 450 |
|
; We try to keep "y" null during all the code, |
| 451 |
|
; so the block copy routine has to be sure that |
| 452 |
|
; y is null on exit |
| 453 |
|
ldy #0 |
| 454 |
|
sty __fetchByte+1 |
| 455 |
|
lda #1 |
| 456 |
|
sta mask_value |
| 457 |
|
|
| 458 |
|
unpack_loop |
| 459 |
|
; Handle bit mask |
| 460 |
|
lsr mask_value |
| 461 |
|
bne end_reload_mask |
| 462 |
|
|
| 463 |
|
jsr GetNextByte ; Read from source stream |
| 464 |
|
|
| 465 |
|
ror |
| 466 |
|
sta mask_value |
| 467 |
|
end_reload_mask |
| 468 |
|
bcc back_copy |
| 469 |
|
|
| 470 |
|
write_byte |
| 471 |
|
; Copy one byte from the source stream |
| 472 |
|
jsr GetNextByte ; Read from source stream |
| 473 |
|
sta (ptr_destination),y |
| 474 |
|
|
| 475 |
|
lda #1 |
| 476 |
|
sta nb_dst |
| 477 |
|
|
| 478 |
|
|
| 479 |
|
|
| 480 |
|
_UnpackEndLoop |
| 481 |
|
;// We increase the current destination pointer, |
| 482 |
|
;// by a given value, white checking if we reach |
| 483 |
|
;// the end of the buffer. |
| 484 |
|
clc |
| 485 |
|
lda ptr_destination |
| 486 |
|
adc nb_dst |
| 487 |
|
sta ptr_destination |
| 488 |
|
|
| 489 |
|
.( |
| 490 |
|
bcc skip |
| 491 |
|
inc ptr_destination+1 |
| 492 |
|
skip |
| 493 |
|
.) |
| 494 |
|
cmp ptr_destination_end |
| 495 |
|
lda ptr_destination+1 |
| 496 |
|
sbc ptr_destination_end+1 |
| 497 |
|
bcc unpack_loop |
| 498 |
|
rts |
| 499 |
|
|
| 500 |
|
|
| 501 |
#include<loader.cod> |
back_copy |
| 502 |
|
;BreakPoint jmp BreakPoint |
| 503 |
|
; Copy a number of bytes from the already unpacked stream |
| 504 |
|
; Here we know that y is null. So no need for clearing it. |
| 505 |
|
; Just be sure it's still null at the end. |
| 506 |
|
; At this point, the source pointer points to a two byte value that actually contains a 4 bits counter, and a 12 bit offset to point back into the depacked stream. |
| 507 |
|
; The counter is in the 4 high order bits. |
| 508 |
|
;clc <== No need, since we access this routie from a BCC |
| 509 |
|
jsr GetNextByte ; Read from source stream |
| 510 |
|
adc #1 |
| 511 |
|
sta offset |
| 512 |
|
jsr GetNextByte ; Read from source stream |
| 513 |
|
tax |
| 514 |
|
and #$0f |
| 515 |
|
adc #0 |
| 516 |
|
sta offset+1 |
| 517 |
|
|
| 518 |
|
txa |
| 519 |
|
lsr |
| 520 |
|
lsr |
| 521 |
|
lsr |
| 522 |
|
lsr |
| 523 |
|
clc |
| 524 |
|
adc #3 |
| 525 |
|
sta nb_dst |
| 526 |
|
|
| 527 |
|
sec |
| 528 |
|
lda ptr_destination |
| 529 |
|
sbc offset |
| 530 |
|
sta ptr_source_back |
| 531 |
|
lda ptr_destination+1 |
| 532 |
|
sbc offset+1 |
| 533 |
|
sta ptr_source_back+1 |
| 534 |
|
|
| 535 |
|
; Beware, in that loop, the direction is important |
| 536 |
|
; since RLE like depacking is done by recopying the |
| 537 |
|
; very same byte just copied... Do not make it a |
| 538 |
|
; reverse loop to achieve some speed gain... |
| 539 |
|
.( |
| 540 |
|
copy_loop |
| 541 |
|
lda (ptr_source_back),y ; Read from already unpacked stream |
| 542 |
|
sta (ptr_destination),y ; Write to destination buffer |
| 543 |
|
iny |
| 544 |
|
cpy nb_dst |
| 545 |
|
bne copy_loop |
| 546 |
|
.) |
| 547 |
|
ldy #0 |
| 548 |
|
beq _UnpackEndLoop |
| 549 |
|
rts |
| 550 |
|
.) |
| 551 |
|
|
| 552 |
|
_EndLoaderCode |
| 553 |
|
|
| 554 |
|
; |
| 555 |
|
; This is free memory that can be used, when it reaches zero then the loader start address should be changed |
| 556 |
|
; |
| 557 |
|
|
| 558 |
|
.dsb $FFF4 - _EndLoaderCode |
| 559 |
|
|
| 560 |
|
_Vectors |
| 561 |
|
|
| 562 |
|
#if ( _Vectors <> $FFF4 ) |
| 563 |
|
#error - Vector address is incorrect, loader will crash |
| 564 |
|
#else |
| 565 |
|
|
| 566 |
|
; |
| 567 |
|
; Here are the functions that the user can call from his own application |
| 568 |
|
; |
| 569 |
|
_ApiSetLoadAddress .byt $4c,<SetLoadAddress,>SetLoadAddress ; $FFF4 |
| 570 |
|
_ApiSetLoadData .byt $4c,<LoadData,>LoadData ; $FFF7 |
| 571 |
|
|
| 572 |
|
; |
| 573 |
|
; These three HAVE to be at these precise adresses, they map to hardware registers |
| 574 |
|
; |
| 575 |
|
_VectorNMI .word IrqDoNothing ; FFFA-FFFB - NMI Vector (Usually points to $0247) |
| 576 |
|
_VectorReset .word IrqDoNothing ; FFFC-FFFD - RESET Vector (Usually points to $F88F) |
| 577 |
|
_VectorIRQ .word IrqHandler ; FFFE-FFFF - IRQ Vector (Normally points to $0244) |
| 578 |
|
|
| 579 |
|
#echo Remaining space in the loader code: |
| 580 |
|
#print (_Vectors - _EndLoaderCode) |
| 581 |
|
|
| 582 |
|
#endif |
| 583 |
|
|
| 584 |
|
; End of the loader - Nothing should come after because it's out of the addressable memory range :) |
| 585 |
|
|
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| 
Revision Log
| 
Patch